Heat-indicator



F. W. SEARS;

HEAT INDIGATOB.. Patented June 21, 1892.

(No Model.)

wif asses All vf ,vv/9,11

me noma Perses cu., muro-umn., wAmImron, u. c.

i UNITE FREDERICK IV. SEARS, OF PROPIIETSTOWN, ILLINOIS.

HEAT-INDICATOR.

SPECIFICATION forming part of Letters Patent No. L77,1313, dated June21, 1892. Application filed December 28V, 189]:- Serial No. 416,353. (Nomodel.)

To all whom, it may concern.-

Be it known that I, FREDERICK W. SEARS, a citizen of the United States,residing at Prophetstown, in the county of Whiteside and State ofIllinois, have invented a new and useful Heat-Indicator, of which thefollowing is a specification.

This invention relates to heat-indicators; and it has for its object toprovide a device of this character which is especially applicable foruse in connection with ordinary stoveovens, the heat of which may beaccurately and definitely determined and regulated by the use of theherein-described indicator, which is designed to be simple inconstruction and Very sensitive to all variations of temperature. Thedevice may also be used in connection with other apparatus in which itis desirable that the temperature thereof be always noted and regulated.

To this end the invention consists in a heatindicator constructed andcombined in the novel manner hereinafter Vmore fully described,illustrated, and claimed.

In the accompanying drawings, Figure 1 is a vertical sectional view of acooking-stove provided with a heat-indicator in connection with the oventhereof and construced in accordance with my invention. Fig. 2 is adetail in perspective of the thermostatic bar and operating-rodconnected therewith. Fig. 3 is a detail sectional view of the indicator.

Referring to the accompanying drawings, VA represents a cooking-stove ofthe ordinary construction and provided with the usual heat-oven B.Secured to one of the sides or walls of said oven is the approximatelyhorizontal thermostatic bar C. The said thermostatic bar C comprises theordinary brass and iron plates c and c', respectively, securely fastenedtogether, in order to provide a bar that will be readily affected byvariations of temperature. One end of said bar is rigidly fastened to abracket D, secured to one of the walls of the oven or otherwise suitablysecured at one end, while the opposite end thereof is left free to moveup or down according to the degree of heat within the oven. It being ofcourse understood that the more rapid expansion and contraction of thebrass will cause the said bar to curve down and resume its normalhorizontal position respectively and being secured at one end, the saidbar, which extends nearly across the full length or width of the oven,is allowed a greater play than usual. Connected to the free end of thethermostatic bar C is the upwardly-extending operatingrod G, passingthrough the top of the oven and the inclosing tube, shield, or guard ebetween the top of the stove and the oven, and is connected at itsextreme upper end to the indicator-actuating arm E of the indicator G'.The said indicator G is suitably supported upon the tp of the stove at aconvenient point of attachment and is provided with an ordinarydial-plate graduated in degrees and over which works the indicating-handI-I. The hand II is carried by a shaft, to the inner end of which issecured the pinion I, engaged by the toothed segment J, mounted upon thesame shaft as the indicator-actuating arm F upon the outside ofthe'casing and connected to the upper end of the operating-rod G. Thenormal position of the thermostatic bar C when the heat is normal holdsthe hand I-I of the indicator at the zero-point of the indicating-dial,and this thermostatic bar thus forms the spring, as it were, of theindicator itself, which controls and regulates the movement of the hand.An increase of heat in the oven causes the top brass plate to expand.more quickly than the under iron plate, and thus curve the outer freeend of the bar downward, which of course draws the operating-bardownward and causes the hand H to revolve and indicate the degree ofheat existing in the oven or other place in which the device is located.

IIaving thus described my invention, what I claim, and desire to secureby Letters Patent, is-

In a heat-indicator for ovens, the combination of a metallicthermostatie bar securely suspended at one end from a suitable Ypoint ofattachment within the oven and having the other end free to move, aheat-indicating device mounted upon the stove and having a pinioncontrolled indicating hand and an actuating-arm, a tube-guard placedbetween the top of the stove and the oven, and an operating-rod workingthrough said tube andA ICO connected to the free end of saidthermostatic bar and to said actuating-arm, said ther.- rnostatic barnormally holding the hand of the indicator at the zero-point and formingthe spring for said indicating mechanism, substantially as set forth.

In testimony that I claim the foregoing as my own have hereto affixed mysignature in the presence of two Witnesses.

FRED. W. SEARS. Witnesses:

FRED. L. ADAMS, W. D. SMITH.

